I got a Summit a few years ago and it works fine. My old RCBS-A2 would not handle some long shell.
It works like the A2. It's marked RC IV on it's side.
The Summit has a left and right hand handle ability, a 1" ram and is geared higher (less mechanical advantage) than the A2.
The A2 has a 1.25" diameter ram which is no advantage to me.
Get the Summit.
It sounds like you are referring to the rock chucker supreme, the summit is new from RCBS and is not an o-frame press.